Plants have many parts; from the roots to the leaves and in some cases, fruit. Each of these parts have vital roles, and could not work without each other: they mesh to form an overall product – whether it be an apple tree to a bush.

The roots anchor the plant in the soil. They also take in water and dissolved minerals, especially nitrates, from the soil. The roots include tiny root hairs, which are efficient at absorbing water as they have a large surface area. The water and dissolved minerals travel through hollow tubes in the stems to the leaves. The leaves are the factories of the plants as such. Here the process of photosynthesis produces food for the plant.

Leaves usually have a large area to absorb the maximum amount of light. They are thin so that the carbon dioxide does not have to travel far through the leaf. The veins in a leaf give the leaf some support and provide the leaf with a supply of water. Carbon dioxide needed for photosynthesis enters through the stomata. Most of the stomata are on the underside of the lead. Stomata open and close. Oxygen and water escape through the stomata. The stomata close at night to prevent too much loss of water.

The waxy layer on the surface of the leaf, called the cuticle, prevents evaporation of water from the surface. Below the cuticle there is a single layer of tightly fitting cells called the epidermis. The palisade cells, below the epidermis but still near to the surface of the leaf, contain a large number of chloroplasts. Chloroplasts contain the chlorophyll and it is here that photosynthesis takes place.

The cells in the spongy layer, below the palisade cells, contains irregularly shaped cells and large air gaps exist between the cells. It is here that oxygen and carbon dioxide gases can be stored. Photosynthesis only occurs in sunlight, the process of aerobic respiration occurs in plants all of the time.